Technology might have come, but this doesn't mean that automatically everyone upgraded to the new firmware
Even until the 1880s, there's hardly any movement in pictures, especially water always looks extremely calm
As I said, more for style then any technical limitations.
Photographers were trying to take photographs like paintings. Painters were painting like photographs.
I've got a publishable essay on this if you would like a copy.
One thing that made some of these civil war photos so detailed looking, or sharp and crisp, is that the way I understand it they used very large "plates" or negatives (typically glass I believe at that time and place) to take their photos...the larger the negatives back then, the sharper the photographs. Not sure exactly what size of negative they used though...the wet plate process was not an easy thing to do.
IN the 1940s and up through the 1960s (and some today) some photographers used a 4 inch by 5 inch film negative, which gave fairly nice detail if the particle size was small enough on the neg. I used a 4 x 5 Speed Graphic camera in the 1960s for several years.
Some of the old glass negatives I have seen were even much larger than that.
on glass negative sizes, I found this quote online:
Typically plate sizes are 9 x 12, 13 x 18, 18 x 24 cm etc. I have only half plates, one set of which date from the USA in 1906 and another set from France around 1910-20. These are all close to 13x18 (or 5" x 7" in imperial) - within 2 or 3 mm in every case
Confederate General Jubal Early in the summer of 1864 reached the outskirts of Washington and skirmished with a couple of the hundreds of forts that surrounded Washington at the time but his army was too small for a direct assault. He did cause Grant to shift troops from his army near Richmond to reinforce the DC garrison.